The present invention relates to a surveying instrument of non-prism type for 3-dimensional measurement.
When 3-dimensional data is to be surveyed on an object such as a building within a predetermined range, there have been disadvantages in the past in that much time was required and there was limitation in acquired amount of the surveying data because an operator must determine a measuring point and surveying operation must be carried out one point after another. By an automatic surveying instrument, in which surveying operation is automated, raster scanning is performed by measuring a predetermined range with fine pitch, and a vast amount of 3-dimensional surveying data can be collected more quickly than in the operation by the surveying operator. By putting together the vast amount of 3-dimensional data, 3-dimensional display can be achieved.
In a conventional type automatic surveying instrument, a great number of measuring points are required, and storage capacity of a storage device to store the data at the measuring points also must be large. In case unnecessary data is incorporated as measuring data, the continuity of the data may be lost, and the measurement must be repeatedly carried out in many cases.
Further, as shown in FIG. 12, when the measuring point is an edge 4 of an object to be measured 3, a distance-measuring light 2 projected from a surveying instrument 1 is divided by the edge 4. A part of the light is reflected by a plane 5 containing the edge 4, and the other part of the light is reflected by a plane 6 beyond the edge 4. As a result, the surveying instrument 1 performs surveying operation based on a reflection light from the plane 5 before the edge 4 and based on a reflection light from the plane 6 beyond the edge 4. This causes a problem that accurate measurement cannot be made on the portion of the edge 4.